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Abstract:

A device for treating blood in an extracorporeal blood circuit, the
device including a centrifugal pump provided with a transparent enclosure
that is connected, by means of an inlet duct, to the outlet of a venous
reservoir, the venous reservoir having an inlet that is connected to
receive blood from a patient. The transparent enclosure of the pump is
connected monolithically to the base of a structure that comprises a heat
exchanger and an oxygenator. The structure also supports monolithically,
at the peripheral region, an arterial filter that receives the blood in
output from the oxygenator and is provided with a connector for coupling
to an arterial line for return of the blood to the patient.

Claims:

1. An integrated device for oxygenating and filtering blood flowing
through an extracorporeal blood circuit comprising: a blood reservoir
having an inlet for receiving venous blood and an outlet for supplying
venous blood; a blood pump having an inlet connected to receive blood
from the outlet of the blood reservoir and an outlet; a heat exchanger
having a blood inlet connected to receive venous blood from the outlet of
the pump and a blood outlet for supplying temperature controlled venous
blood; an oxygenator having an inlet connected to receive venous blood
from the outlet of the heat exchanger and an outlet for supplying
oxygenated blood; an arterial blood filter having an inlet connected to
receive oxygenated blood from the outlet of the oxygenator and an outlet
for supplying filtered oxygenated blood; and a monolithic housing
including a first portion for defining the blood reservoir, a second
portion for defining the blood pump, a third portion for defining the
heat exchanger, a fourth portion for defining the oxygenator and a fifth
portion for defining the arterial blood filter, the second portion being
configured such that the outlet of the blood pump is located at a top of
the second portion of the monolithic housing.

3. The integrated device of claim 2 wherein the centrifugal pump has an
axis and wherein the centrifugal pump is positioned within the monolithic
housing such that the axis of the centrifugal pump is horizontal.

4. The integrated device of claim 1 wherein the blood reservoir comprises
a venous reservoir and a cardiotomy reservoir.

5. The integrated device of claim 4 wherein the monolithic housing
comprises connection means for allowing removable connection of the first
portion.

6. A system for establishing an extracorporeal blood circuit comprising:
a blood reservoir; a blood pump; a heat exchanger; an oxygenator; an
arterial blood filter; and a housing for incorporating and
interconnecting the blood reservoir, the blood pump, the heat exchanger,
the oxygenator and the arterial blood filter into a monolithic structure,
the housing having an inlet for supplying venous blood to the blood
reservoir and an outlet for supplying oxygenated blood from the arterial
blood filter, the housing further having a portion which defines the
blood pump including a blood pump inlet and a blood pump outlet, the
outlet of the blood pump being located at a top of the portion.

7. The system of claim 6 wherein the blood pump comprises a centrifugal
pump.

8. The system of claim 7 wherein the centrifugal pump has an axis and
wherein the centrifugal pump is positioned within the housing such that
the axis of the centrifugal pump is horizontal.

9. The system of claim 6 wherein the blood reservoir comprises a venous
reservoir and a cardiotomy reservoir.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of U.S. application Ser. No.
12/331,082, filed Dec. 9, 2008, entitled "Device and Methods for
Processing Blood in Extracorporeal Circulation", which is a continuation
of U.S. Pat. No. 7,476,359, filed Mar. 18, 2004, entitled "Device and
Methods for Processing Blood in Extracorporeal Circulation"; which claims
foreign priority of Italian Patent Application No. MI2003U000148, filed
Apr. 1, 2003, all of which are hereby incorporated herein by reference in
their entireties.

FIELD OF THE INVENTION

[0002] The invention relates to a method and device for processing blood
in extracorporeal circulation. Reference is made to co-pending
application U.S. Publn. No. 2004/0219060, filed on Mar. 18, 2004, and
entitled "Device and Methods for Processing Blood in Extracorporeal
Circulation" which is assigned to the assignee of the present invention
and which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

[0003] During certain surgical procedures it is necessary to establish a
circuit for extracorporeal circulation of the blood of the patient. Such
circuits may comprise devices such as blood reservoirs which may include
a venous reservoir, that is meant to collect the blood that leaves the
patient, and a cardiotomy reservoir for containing the blood drawn by
recovery from the operating field, a pump for conveying blood in the
circuit, a heat exchanger in which the blood encounters a heat exchange
surface that maintains blood temperature at a desired value, an
oxygenation device that is meant to transfer oxygen to the blood, and
finally a filter known as an arterial filter, that is connected in the
arterial line and is meant to retain any air bubbles that are present in
the blood before the blood is returned to the patient.

[0004] All these devices can be present in the extracorporeal circuit as
separate elements or they can be integrated in various combinations such
as disclosed in co-pending U.S. patent application Ser. No. 09/920,999
filed Aug. 2, 2001, (U.S. Pat. No. 6,723,283) which is assigned to the
assignee of the present invention, and which is incorporated herein by
reference in its entirety.

[0005] A need in this field exists, however, for a monolithic structure
which integrates into a single package all of the various components
necessary for use in an extracorporeal blood circuit used during heart
bypass surgery or as an assist circuit during beating heart surgery.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provide a device that
ensures optimum conditions of removal of the air contained in the device
during priming and use and which is configured to allow an operator of
the device to maintain visual contact with critical portions of the
device during use so that the operator can take corrective action when a
problem situation is observed.

[0007] This object and other objects that will become better apparent
hereinafter are achieved by a device for treating blood in extracorporeal
circulation that comprises an integrated structure that includes a venous
reservoir, a cardiotomy reservoir, a centrifugal blood pump, an
oxygenator, a heat exchanger and an arterial blood filter, all of which
are inter connected by means of various tubing lines and/or ducts. The
integrated structure forms a complete system which includes all of the
components required in an extracorporeal blood circuit used during heart
bypass surgery or used to assist the heart during beating heart surgery.
The integrated structure is configured to be shipped to a user as a
completely assembled and interconnected system or alternatively, to more
efficiently use packaging space some minimal assembly might be required
by the user.

[0008] The integrated structure includes a centrifugal pump provided with
a transparent enclosure that is connected, by means of an inlet duct, to
the outlet of the venous reservoir. The inlet of the venous reservoir is
connected to a venous line for conveying the blood from a patient. The
transparent enclosure of the centrifugal pump is connected to the portion
of the unitary structure that comprises the heat exchanger and
oxygenator. The centrifugal pump may be a standard component which
connects to the structure in a manner known in the art. Usually the
centrifugal pump will be connected prior to packaging so that it is
shipped and is received by the user as part of the monolithic structure
although it could be shipped unconnected from the structure and connected
by the user after receipt. That portion of the unitary structure
comprising the oxygenator/heat exchanger has an inlet connected to
receive blood from the centrifugal blood pump and also supports
monolithically, at a peripheral region, the arterial filter. The arterial
filter has an inlet connected to receive blood from an outlet of the
oxygenator/heat exchanger. The arterial filter has an outlet connected to
an arterial line for return of the blood to the patient.

[0009] In one embodiment the invention comprises an integrated device for
oxygenating and filtering blood flowing through an extracorporeal blood
circuit. The integrated device comprises a blood reservoir having an
inlet for receiving venous blood and an outlet for supplying venous
blood. The device includes a blood pump having an inlet connected to
receive blood from the outlet of the blood reservoir and an outlet
connected to a blood inlet of a heat exchanger. The heat exchanger has a
blood outlet for supplying temperature controlled venous blood to the
inlet of an oxygenator. The oxygenator has an outlet for supplying
oxygenated blood to the inlet of an arterial blood filter. The arterial
blood filter has an outlet adapted for connection to an arterial line for
return of oxygenated blood to the patient. The integrated device includes
a monolithic housing having a first portion for defining the blood
reservoir, a second portion for defining the blood pump, a third portion
for defining the heat exchanger, a fourth portion for defining the
oxygenator and a fifth portion for defining the arterial blood filter.

[0010] The blood pump may comprise a centrifugal pump that is positioned
within the monolithic housing such that an axis of the centrifugal pump
is horizontal. The blood reservoir may comprise a combined venous
reservoir and cardiotomy reservoir. Further, the monolithic housing of
the integrated device may comprise connection means which allows
removable connection of the first portion or the second portion of the
housing.

[0011] In another embodiment the invention comprises a system for
establishing an extracorporeal blood circuit. The system includes a blood
reservoir, a blood pump, a heat exchanger, an oxygenator, an arterial
blood filter and a housing for incorporating and interconnecting the
blood reservoir, the blood pump, the heat exchanger, the oxygenator, and
the arterial blood filter into a monolithic structure. The housing has an
inlet for receiving venous blood from a patient and supplying the venous
blood to the blood reservoir and an outlet for supplying oxygenated blood
from the arterial blood filter to a patient.

[0012] The blood pump may comprise a centrifugal pump which is positioned
within the housing such that an axis of the pump is horizontal. The blood
reservoir may comprise a combined venous reservoir and cardiotomy
reservoir. Further, the housing may comprise connection means for
allowing removable connection of the blood reservoir or the centrifugal
blood pump.

[0013] While multiple embodiments are disclosed, still other embodiments
of the present invention will become apparent to those skilled in the art
from the following detailed description, which shows and describes
illustrative embodiments of the invention. Accordingly, the drawings and
detailed description are to be regarded as illustrative in nature and not
restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Further characteristics and advantages will become better apparent
from the description of two embodiments of the invention, illustrated by
way of nonlimiting example in the accompanying drawings.

[0015] FIG. 1 is a longitudinal sectional view of the invention.

[0016] FIG. 2 is another longitudinal sectional view of the invention
according to a different embodiment of the venous reservoir.

[0017] While the invention is amenable to various modifications and
alternative forms, specific embodiments have been shown by way of example
in the drawings and are described in detail below. The intention,
however, is not to limit the invention to the particular embodiments
described. On the contrary, the invention is intended to cover all
modifications, equivalents, and alternatives falling within the scope of
the invention as defined by the appended claims.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] With reference to FIG. 1, the reference numeral 1 generally
designates the device according to the invention, which comprises various
components which have been integrated into a unitary or monolithic
structure. These components are interconnected by various tubing lines or
ducts to establish a blood flow path through the unitary structure
according to the arrows shown in the figures and which will be described
in detail, hereafter.

[0019] The unitary structure includes a venous reservoir 2, which is
provided with an input connector 2a for connection to a venous line for
receiving blood from the patient. Blood received from the patient through
connector 2a passes through a filter 2b before it reaches venous
reservoir 2. A cardiotomy reservoir 2c is contained within venous
reservoir 2 and is connected receive blood recovered from the operating
field through an inlet connector 2d. Blood received through inlet
connector 2d passes through a filter 2e before it reaches venous
reservoir 2.

[0020] An outlet connector 2f of venous reservoir 2 is connected at one
end of duct 3. The other end of duct 3 is connected to an inlet of
centrifugal pump 4. Centrifugal pump 4 has a transparent enclosure which
defines an outlet connector 4b which is connected to delivery duct 4a,
connected to provide blood from centrifugal pump 4 to an inlet connector
5a of heat exchanger 5. Heat exchanger 5 is provided with an outlet
connector 5b that is configured to convey the blood to inlet 6a of
oxygenator 6.

[0021] From the outlet 6b of the oxygenator 6, the blood reaches arterial
filter 7, which is provided with an outlet connector 7a for connection to
an arterial line for the return of the blood to the patient.

[0022] The transparent enclosure of the centrifugal pump 4 is connected
monolithically to the end face of the structure that comprises the heat
exchanger 5 and the oxygenator 6. Centrifugal pump 4 is oriented so that
the pump axis is horizontal and outlet connector 4b is positioned at the
top of the pump. This arrangement is beneficial for several reasons.
First, it essentially ensures the complete removal of any air contained
in the pump during its filling since any air bubbles in the device will
rise because of their buoyancy and be expelled through the outlet
connector at the top of the pump. Second, since the axis of the
centrifugal pump is horizontal the entire rotor and pump chamber are
visible to the operator through the transparent enclosure. This allows
the operator to visually locate any air bubbles which may pass into or
through the pump and to take appropriate corrective action in response
thereto.

[0023] Furthermore, the ease with which the device may be set up and its
operating convenience are both enhanced by the fact that the venous
reservoir 2 is removably connected to a pedestal 8 that protrudes from
that portion of the unitary structure that comprises the heat exchanger
and the oxygenator by virtue of snap-acting means. This allows the venous
reservoir/cardioplegia reservoir to be constructed as a first module of
the system and the oxygenator/heat exchanger/arterial filter/pump to be
constructed as a second module of the system. These two modules can be
detached during shipment to conserve package space and assembled by the
user by snap fitting the modules together during set up. Alternatively,
they can be shipped completely assembled.

[0024] The embodiment shown in FIG. 2 differs from the one described above
only in that rigid or hard shell venous reservoir 2 is replaced by a
flexible bag 9. Bag 9 is connected to a support 10 that extends from the
structure that comprises the heat exchanger and the oxygenator and is
provided with an inlet connector 9a for connection to a venous blood
inlet line and with an outlet connector 9b that is connected to the inlet
of pump 4 through duct 3.

[0025] The device of the present invention may be used as a fast,
efficient and convenient alterative to the use of various individual
components in a traditional extracorporeal blood circuit. Since the
structure of the device incorporates these various individual components
into a preconnected monolithic structure it can be set up and ready for
use very quickly. Further, the present invention is advantageous for use
in beating heart surgery for several reasons. First, since part of the
blood is diverted into an extracorporeal circuit the heart has less blood
to pump and therefore beats less making it easier for the surgeon to work
on the heart. Second, in cases where it is necessary to change to full
bypass during the surgery the monolithic device of the present invention
includes an oxygenator and other components which provide the capacity
and function necessary to accommodate the change. The present invention
also includes methods of using the device to process blood during heart
bypass or beating heart surgery.

[0026] It should be understood that the embodiments disclosed herein
represent presently preferred embodiments of the invention. Various
modifications and additions may be made to these embodiments without
departing from the spirit and scope of the invention.

[0027] Various modifications and additions can be made to the exemplary
embodiments discussed without departing from the scope of the present
invention. For example, while the embodiments described above refer to
particular features, the scope of this invention also includes
embodiments having different combinations of features and embodiments
that do not include all of the described features. Accordingly, the scope
of the present invention is intended to embrace all such alternatives,
modifications, and variations as fall within the scope of the claims,
together with all equivalents thereof.